From Slashdot:

Opera is celebrating its 10th anniversary, and is giving away free registrations for its browser. For those of you without an educational site license (pass that link to your friendly sysadmin!), you can get a free registration as long as the party lasts - probably for the next few hours or so - and stop getting bugged by advertisements.

Handy for those few websites out there that still refuse to work with Firefox (unfortunately, they exist), even when you spoof your User Agent to pretend ot be IE on Windows.